To activate means to make it active. If you want more out of audio books you need to get active while listening. I recommend making notes or mind mapping. Using the hand while listening triggers a better memory.
On the whole you will only remember about 30% of what is said during a lecture or recording. So be selective. If you hear something that you want to put into action. Put it into action. The follow through will help more of what you heard become yours.
Alex
